Muffler



R. B. KUHN Feb. 19, 1946.

MUFFLER Filed April 8, 1944 3mm Rob eI'' B. Kuhn w W 'iv/M Patented cb. 19, 1,946

UNITED STATES PATENT oF'FicE 9 Clalm's.

The invention relates to mulilers for the exhaust of internal combustion engines, and more particularly to a mufller of the cup type in which a plurality of substantially similar cups are vassembled upon the exhaust pipe of an engine.

It'is an objectof the invention to provide a simple, emcient and low-cost mufller made entirely of sheet metal stampings capable of mass production.

Another object is to provide a mufller having a plurality of expansion chambers communicating with each other through contracted openings.

Still another object is to provide a mufller that will effectively silence the noise due to the exhaust of gases coming 'from an internal combustion engine without producing any undesirable high back pressure.

A further object is the provision of a mufiler formed of a plurality of similar cup-like sections, whereby it can be readily added to or subtracted from to adjust the muflier to any particular design of engine to which it may be deslrable to attach it.

It is a still further object of the invention to provide a muflier comprising a plurality of expanslon chambers communicating with each other through eccentrically located openings so arranged that a portion of each openingis located in the axial center of the muifler whereby a portion of the exhaust gases pass axially through the mufller while the remainder of the exhaust gases travel spirally around the axis of the mufiier and expand within the several chambers of the mufller.

Still another object is to provide a muliier made of a plurality of sheet metal sections each of which has a protective covering of vitreous enamel thereon to protect the metal from rust.

The above objects together with others which will be apparent from the drawing and following description or which may later be referred to, may be attained by construoting the improved mufller in the manner illustrated in the-accompanying drawing in which:

Figure 1 is a longitudinal sectional view through a `muiller constructed in accordance with the invention; A

Fig. 2 a transverse section through the mufiler, taken on the line 2--2, Figure 1 and Fig. 3 a sectional view taken on the line 3 3, Figure 1.

Referring now to the drawing, in which similar at IO, each comprising the bottom wall II with an eccentric opening IZ therein surrounded by an inturned annular flange I3, and a substantially cylindrical side wall Il having an inwardly disposed annular bead IS near its edge and terminating in the enlarged cylindrical flange portion IB of such diameter as to snugly fitover the bottom portion of similar cup sections.

In assembling the mufller any desired number of these cup sections may be placed together in the manner shown in Fig. 1, the number of the Sections used depending upon the particular engine to which it is desired to attach the mufller.

At the end of the mufller toward the exhaust pipe I'I of the engine a disc I8 is fitted into the open end of the next adjacent cup section III, this disc having a peripheral flange IS of .proper dimensions to snugly fit within the outr fiange portion IB of the cup section.

The disc I8 is provided at its center with a concentric opening 20, of substantially the same size as the openings I2 in the bottom walls II of the cup Sections, this opening 20 being surrounded by an elongated, cylindrical neck 2| of suitable dimensions to fit snugly around the end of the exhaust pipe I'l from the engine. This neck 2| may be clamped or otherwise rigidly attached to the exhaust pipe I'I in any usual and wellknown manner.

At the opposite, or exhaust, end of the mufiler is provided a cylindrical section 22 having an ann ular bead Ia and terminal flange Ia at one end adapted to receive the bottom portion of the adjacent cup section IO and provided at its other end with the annular bead I5b and terminal flange IGb, to receive the annular flange portion I9a of the end disc I8a.

The disc I8a is provided at its center with the concentric opening 20a of substantially the diameter of the openings I2'in the cup Sections, said opening being surrounded by the cylindrical exhaust neck 2Ia through which the exhaust'l gases are discharged from the muffler.

A plurality of small apertures 23 may be located at 'equallyrspaced points near the peripheries of the bottom walls II of the cup sections and the end discs I 8 and I 8a to receive the tie rods 24 which are provided at one end with heads 25 for contacting the outer surfaces of one of the end discs, the opposite ends thereof being screw threaded as at 26 to receive the nuts 21 which contact the outer surfaces of the other end disc to hold all of the parts ia assembled condition as shown in the drawing.

In order toiprevent the sheet metal parts of the mufiier from being attacked by rust or corrosion each part is preferably coated with a vitreous enamel such as is commonly used upon enameled sheet metal cooking utensils and the like.

In assembling the mufiler the cup sections H) are so positioned that the eccentric openings l2 in the bottom wall of each cup section are located at a 120 angle beyond the next preceding opening |2 as best shown in Figs. 2 and 3, so that the openings |2 are located spirally around the longitudinal axis of the muilier, a portion of each opening overlapping the longitudinal axis of the muffier as indicated at 28 in Figs. 2 and 3.

This provides for a straight axial path through the center of the mufiier through which a portion of the exhaust gases may pass in a straight line from the exhaust pipe ll to the exhaust neck 21a of the mutiier, while the remainder of the exhaust gases will travel in a spiral path around the axis permitting this portion of the gases to expand in each of the cup chambers 29 so as to effectively silence the noise due to the exhaust gases coming from the engine.

The portion of the exhaust gases traveling in a straight line axially through the center of the mufiier will act in the manner of an injector to suck the expanding gases from the expansion chambers and carry them out of the muilier.

From the above it will be obvious that the improved form of a muifier not only provides for'a portion of the gases to travel spirally around the axis of the muflier and to expand in each of the chambers 29 but by permitting a portion of the exhaust gases to travel in a straight line axially throughV the muiller, these expanding gases will be continuously withdrawn from the muiiler preventing any back pressure.

It will further be seen that the enameled surfaces of the muiiler will be protected against rust or corrosion and that the entire mufiier may be readily taken apart for cleaning, repairing or readjusting.

I claim:

i. A muiiier of hollow cylindric form having a plurality of spaced transverse walls dividing the interor of the muiiier into a plurality of expansion chambers, means for connecting one end of the mufiler to the exhaust pipe of an engine,

there being an exhaust outlet at the other end.

of the mufer, each of said transverse walls having an eccentric opening therein, said openings being spirally staggered around the longitudinal axis of the muffier and a portion only of each opening overlapping the longitudinal axis of the mufer, the longitudinal axial portion of the muffler being entirely unobstructed.

2. A muflier of holiow cylindric form 'having a plurality of spaced transverse walls dividing the interior of the muiiier into a plurality of expansion chambers, means for connecting one end of the muiiier axially to the exhaust pipe of an engine, there being an axial exhaust outlet at the other end of the muiiier, each of said transverse walls having an eccentric opening therein, said openngs being spirally staggered around the longitudinal axis of the mufiier and a portion only of each opening overlapping the longitudinal axis of the mufiler, the longitudinal axial portion of the muiiier being entirely unobstructed.

3. A :numer of hollow cylindric form having a plurality of spaced transverse walls dividing the interior of the :numer into a plurality of expansion chambers, means for connecting one end of the muiiier to the exhaust pipe of an engine,

vthere being an exhaust outlet at the other end of the mufller, each of said transverse walls having an eccentric opening therein, a peripheral fiange around each opening and disposed toward the exhaust pipe of the engine. said openings being spirally staggered around the longitudinal axis of the mumer and a portion only of each opening overlapping the longitudinal axis of the mulller, the longitudinal axial portion of the muffier being entirely unobstructed.

4. A muiiier of hollow cylindric form having a i plurality of spaced transverse walls dividing the interior of the :numer into a plurality of expansion chambers, means for connecting one end of the muiiier axially to the exhaust pipe of an engine, there being an axial exhaust outlet at the other end of the mufller, each of said transverse walls having an eccentric opening therein. a peripheral fiange around each opening and disposed toward the exhaust pipe of the engine, said cpenings being spirally staggered around the longitudinal axis of the mufller and a portion only of each opening overlapping the longitudinal axis of the mui'fler, the longitudinal axial portion of the muilier being entirely unobstructed.

5. A muiiier comprising a plurality of cup-like sections each having an inwardly disposed annular concavo-convex bead near its open end and an enlarged annular fiange beyond said head for iitting over the closed end of the next adjacent section, the bottom wall of each cup-like section having an eccentric opening therein, said openings being spirally staggered around the longitudinal axis of the muiiier and a portion only of each opening overlapping the longitudinal axis of the muiiier the longitudinal axial portion of the muiiler being entirely unobstructed, means for connecting one end of the mufller to the exhaust pipe of an engine and an exhaust Outlet at the other end of the muffler.

6. A muiiler comprising a plurality of cup-like Sections each having an inwardly disposed annular concavo-convex bead near its open end and an enlarged annular fiange beyond said bead for fitting over the closed end of the next adjacent section, the bottom wall of each cup-like section having an eccentric opening therein, said openings being spirally staggered around the longitudinal axis of the muflier and a portion only of each opening overlapping the longitudinal axis of the muflier the longitudinal axial portion of the muifier being entirely unobstructed, means for connecting one end of the mumer to the exhaust pipe of an engine and an exhaust outlet at the other end of the muiiler each of said Sections being coated with a vitreous enamel.

7. A mui'iier comprising a plurality of cup-like Sections each having an inwardly disposed annular concavo-convex bead near its open end and an enlarged annular flange beyond said bead for fitting over the closed end of the next adjacent section, the bottom wall of each cup-like section having an eccentric opening therein, said openings being spirally staggered around the longitudinal axis of the muiiier and a portion only of each opening overlapping the longitudinal axis of the muiiier the longitudinal axial portion of the muiiier being entirely unobstructed. means for connecting one end of the mumer axially to the exhaust pipe of an engine and an axial exhaust outlet at the other end of the mufiler.

8. A mufiler comprising a plurality of cup-like sections each having an inwardly disposed annular concavo-convex bead near its open end and an enlarged annular nange beyond said bead for fitting over the closed end of the next adjacent section, the bottom wall of each cup-like section having an eccentric opening therein, said openings being spirally staggered around the longitudinal axis of the mufiier and a portion only of each opening overlapping the longitudinal axis of the muflier the longitudinal axial portion of the mufiier being entireiy unobstructed, means for connecting one end of the mufiier to the exhaust pipe of an engine and an exhaust outlet at the other end of the muiiier and a peripheral fiange around each opening and disposed toward the exhaust pipe of the engine.

9. A mufiier comprising a plurality of cup-like Sections each having an inwardly disposed an- 15 nuiar concavo-convex head near its open end and an enlarged annuiar fiange beyond said bead for fitting over the closed end of the next adjacent section, the bottom wall of each cup-like section having an eccentric opening therein, said openings being spiraiiy staggered around the iongitudinal axis of the mufiier and a portion only of each opening overlapping the Iongitudinal axis of the muifler the longitudinal axial portion of the mufiier being entirely unobstructed, means for connecting one end of the muflier axially to the exhaust pipe of an engine and an axial exhaust outlet at the other end of the mufl'ier.

ROBERT B. 

